1. Field of the Invention
The present invention is related to shoes and, more particularly, is directed towards a new and improved shoe sole construction which features novel midsole and outsole structure.
2. Description of the Prior Art
Many shoe sole constructions have been advanced which attempt to provide maximum comfort and stability for the foot. Other constructions aim at achieving maximum flexibility of the sole. Still other shoe sole constructions, notably in the field of running shoes, attempt to provide as lightweight a shoe as possible while achieving maximum foot stability, shock absorption, and outsole wear. Recently, greater attention has been paid, particularly in the running shoe field, towards providing greater shock absorption to minimize the introduction of impact-induced shock components back into the shoe, foot and leg of the runner. Exemplary of the latter feature is the running shoe disclosed and claimed in my co-pending U.S. patent application Ser. No. 935,584, filed Aug. 21, 1978, which is expressly incorporated herein by reference.
A problem with the prior art footwear in general has been that the requirements of comfort, stability, support, flexibility, lightweightness and long-wearability are difficult to achieve in a single sole construction. Frequently, one of the preceding goals may be achieved in a particular sole design at the expense of another. For example, it is known that to provide long-lasting outsoles, the latter should be made of a relatively dense, durable material which, it may be appreciated, limits its flexibility and foot-cushioning ability. Although it is also known, for example, in a running shoe to provide a relatively dense, hard outsole with a softer midsole, the ability of the soft midsole to cushion the foot during foot-induced ground impact is necessarily limited by the harder outsole which is positioned between the midsole and the ground upon impact.
Women's high-heeled footwear, in particular, has a long way to go to achieve maximum comfort for the wearer. Due to the high-heeled design, women wearing such shoes typically experience rather severe stresses in their transverse metatarsal arches in the forefoot of the shoe. This is due to the weight placed upon the metatarsal arches as a result of the elevated heel and instep.
Men's footwear, albeit to a lesser degree, suffer from many of the same deficiencies.
Accordingly, it may be appreciated that the prior art footwear, especially the sole construction thereof, is severely deficient in failing to achieve all of the desired attributes mentioned above in a single sole construction. It is towards this end that the present invention is advanced.
Prior art patents which may relate to the present invention include: U.S. Pat. Nos. 2,199,853; 2,201,300; and 2,745,197; British Pat. No. 19,548 (1891); German Pat. No. 680,698 (1939); and French Pat. No. 2,269,881 (1975).